Powder separator



POWDER SEPARATOR' Filed Jan. 18, 1952 A.C.SOURCE IN VEN TOR. EDWARDA.HAMACHER AGENT United States Patent "ice POWDER SEPARATOR Edward A. Hamacher, North Tarrytown, N. Y., assignor,

by mesne assignments, to North American Philips Company, Inc., New York, N. Y., a corporation of Delaware Application January 18, 1952, Serial No. 267,073

Claims. (Cl. 209-364) This invention relates to powder separators and more particularly to the type which is used in separating powder for use in X-ray difl'raction.

An object of the invention is to provide a separator which is extremely quiet in operation and hence ex tremely advantageous in laboratory use.

A further object of the invention is to provide a powder separator with a minimum number of external moving parts.

A still further object of the invention is to provide an improved and simplified form of a vibrating type of powder separator which can be readily controlled while at rest or during operation.

Another object of the invention is to provide a powder separator in which use is made of the vibrating diaphragm to impart its energy to the mesh to be vibrated through the medium of an air column rather than by any mechanical means.

The invention relates 'to a powder separator which is particularly useful in separating from a powder mixture a fraction whose grain size is less than the specified size. It is frequently desirable in the laboratory, for example in X-ray powder techniques, to use a powder sample whose grain size is small enough to get good averaging of diffracted X-rays over the surface of the sample. Heretofore, the powder separator used in obtaining such a powder sample comprised a container with an open bottom across which is stretched a wire, cloth or metal mesh whose openings were just large enough to pass the particles desired in the separated fraction. The powder sample was obtained by placing an unseparated mixture in the container and by mechanically vibrating the container, usually in a vertical direction until a desired amount had passed through the mesh. While this type of device is satisfactory in separating the powder, due to the vibrating mechanism in vibrating the container, it is very noisy and most disturbing to those working in the laboratory. The present device eliminates this extremely undesirable noise. It has been found that when using a flexible mesh with the aforementioned conventional type of separator, the mesh will vibrate in synchronism with the container principally because of the inertia of the powder mixture. This phenomenon is used as the basis for the present invention which consists of a vessel which does not move but which is mounted on a rigid support. The inside of this vessel which contains the unseparated mixture is connected by an air column to the inside of the second vessel in which is mounted a diaphragm or piston which is vibrated in any convenient manner. Since the system is enclosed, most of the energy imparted to the air by vibrating the diaphragm will be transmitted to the flexible mesh acting as a diaphragm so that the mesh will be vibrated. By vibrating the mesh, the unseparated mixture resting on the mesh will be agitated causing separation of the desired fraction. In essence, the powder mixture and mesh are air coupled rather than mechanically coupled to the vibrating mechanism.

Any type of driver may be used to vibrate the diaphragm for example, as shown in the preferred embodiment, an electro-acoustical device such as a dynamic speaker may be used. The amplitude of the vibration and hence the speed in which the material passes through the mesh is thus easily adjusted by varying the power applied to the driver, for example, by means of a variable resistance. By completely enclosing the system any back sound radiation is eliminated.

2,695,102 Patented Nov. 23,

With the foregoing and other features as objects in view, as will appear in the following specification and claims taken in connection with the accompanying drawing herein, the figure illustrated shows an elevation view of the preferred embodiment in accord with the present invention.

Referring now to the drawing, a driver element 1 such as an electro-acoustical driver, for example a dynamic speaker, is shown which vibrates the diaphragm 2, located in the vessel 3. Integral with vessel 3 is a cylindrical air column 4 which is rigidly supported by any conventional support means as indicated at 5 and 6. A vessel 7 which is the container for the unseparated powder, is open at one end 8 and closed at the other end by a sieve member 9 of any suitable material such as a cloth or wire mesh which has openings of such a size so that only the preferred size of powder grain will pass therethrough. The powder 10 is placed in the vessel 7 and the vessel in turn is placed over the open end 14 of the air column 4, being coupled thereto by any type of coupling such as shown at 15, which coupling not only supports the vessel 7 on the air column 4 but also seals the open end 8 so that the system will be entirely closed. The driver 1 can be electrically driven by an electrical power source such as indicated at 11, the power supply to said driver being controlled by a variable resistance indicated at 12 which is in series with the transformer 13 of the electro-acoustical driver.

Assuming, for example, that the driver 1 is a dynamic speaker, the voice coil of the speaker is excited by 60 cycles from a small filament transformer such as indicated at 13 which excitation causes the diaphragm 2 to vibrate, imparting energy to the air within vessel 3, column 4, and vessel 7, which energy is transmitted to the flexible mesh 9 thereby vibrating the mesh and causing agitation of the unseparated mixture 10 so that the particles which are small enough to pass through the openings in the mesh will fall by gravity through said mesh into the container 16. In order to control the rate at which the material passes through the mesh, a variable resistance 12 is used to control the power applied to the speaker thus controlling the amplitude of the vibration of the diaphragm 2.

Obviously those skilled in the art may make various changes in the details of the arrangement of parts, such as substituting another type of driver for the vibrating diaphragm, without departing from the spirit or scope of the invention as defined by the claims hereto appended.

Having thus described and shown a working embodiment of my invention, I claim as my invention:

1. A powder separator for separating particles of less than a predetermined size from a mixture of powder, comprising first means enclosing a column of air, a diaphragm enclosing one end of said means, means to vibrate said diaphragm, a separate container connected to the other end of said first means, coupling means between said first means and said container to support said container on said first means and to form a seal between said container and said first means, and flexible mesh means forming the bottom of said container and adapted to support the unseparated mixture of powder, said mesh means being vibrated by said diaphragm through the medium of said column of air upon the application of said means to vibrate said diaphragm.

2. A powder separator for separating particles of less than a predetermined size from a mixture of powder, comprising an upright vessel enclosing a column of air, means to rigidly support said vessel, a diaphragm enclosing the top end of said vessel, means to vibrate said diaphragm, a separate container connected to the bottom end of said vessel, coupling means between said vessel and said container to support said container on said vessel and to form a seal between said container and said vessel, and flexible mesh means forming the bottom of said container and adapted to support the unseparated mixture of powder, said mesh means being vibrated by said diaphragm through the medium of said column of air upon the application of said means to vibrate said diaphragm.

3. A powder separator for separating particles of less than a predetermined size from a mixture of powder,

comprising an upright vessel enclosing a column of air, means to rigidly support said vessel, a diaphragm enclosing the top of said vessel, driving means to vibrate said diaphragm, a container connected to the other end of said vessel, coupling means between said vessel and said container to support said container on said vessel and to form a seal between said container and said vessel, and flexible mesh means forming the bottom of said container and adapted to support the unseparated mixture of powder, said driving means comprising a dynamic speaker having a diaphragm and an electric power driving source driving said diaphragm, and said mesh means being vibrated by said diaphragm through the medium of said column of air upon the application of said electric power driving source to vibrate said diaphragm.

4. A powder separator for separating particles of less than a predetermined size from a mixture of powder, comprising an upright vessel enclosing a column of air, means to rigidly support said vessel, a diaphragm enclosing the top end of said vessel, driving means to vibrate said diaphragm, a separate container connected to the other end of said vessel, coupling means between said vessel and said container to support said container on said vessel and to form a seal between said container and said vessel, flexible mesh means forming the bottom on said container and adapted to support the unseparated mixture of powder and means to regulate said driving means to control the rate at which the powder is separated, said mesh means being vibrated by said diaphragm through the medium of said column of air upon the application of said driving means to vibrate said diaphragm.

5. A powder separator for separating particles of less than a predetermined size from a mixture of powder, comprising an upright vessel enclosing a column of air, means to rigidly support said vessel, a diaphragm enclosing the top end of said vessel, a dynamic speaker to vibrate said diaphragm, a container connected to the other end of said vessel, coupling means between said vessel and said container to support said container on said vessel and to form a seal between said container and said vessel, flexible mesh means forming the bottom of said container and adapted to support the unseparated mixture of powder, an electric power source to supply electric energy to said dynamic speaker, and a variable resistor to control the amount of said power supplied to said electric power source.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 51,662 Seymour Dec. 19, 1865 1,530,193 Montgomery Mar. 17, 1925 1,758,422 Anderson May 13, 1930 2,200,472 Erdmann May 14, 1940 2,241,842 Brusset May 13, 1941 2,394,613 Houlgate et a1 Feb. 12, 1946 

